Processo para a remoção de contaminantes ácidos gasosos de uma corrente de alimentação hidrocarbônica gasosa, e, uso do retentato rico em hidrocarboneto

摘要

The invention concerns a process for the removal of gaseous acidic contaminants, especially carbon dioxide and/or hydrogen sulphide, in two or more stages from a gaseous hydrocarbonaceous feedstream (1) comprising hydrocarbons and said acidic contaminants, using one or more membranes in each separation stages. The gaseous hydrocarbonaceous feedstream is especially a natural gas stream. The process is especially suitable for feedstreams comprising high amounts of acidic contaminants, e.g. between 10 and 95 vol. % of carbon dioxide and/or hydrogen sulphide, especially between 15 and 70 vol. %. In a first stage (2) a clean or almost clean hydrocarbon stream (3) is separated from the feedstream, the hydrocarbon stream suitably containing less than 5 vol % of acidic contaminants. The remaining stream (4) comprises the acidic contaminants and a certain amount of hydrocarbons. In a second stage (6) a pure or almost pure stream of acidic contaminants (8) is separated from the remaining stream (7), where after the then remaining stream is combined with the feed for the first stage (1), the acidic contaminants stream suitably containing less than 5 vol % of hydrocarbons.